MongoDB数据表基本操作
查看全部数据表> use ChatRoomswitched to dbChatRoom> showcollectionsAccountChatsystem.indexessystem.users
创建数据表
>db.createCollection("Account"){"ok":1}
>db.createCollection("Test",{capped:true, size:10000}) {"ok" : 1 }
{"ok":1}--说明
capped:true，表示该集合的结构不能被修改；
size:在建表之初就指定一定的空间大小，接下来的插入操作会不断地按顺序APPEND数据在这个预分配好空间的文件中，如果已经超出空间大小，则回到文件头覆盖原来的数据继续插入。这种结构保证了插入和查询的高效性，它不允许删除单个记录，更新的也有限制：不能超过原有记录的大小。这种表效率很高，它适用于一些暂时保存数据的场合，比如网站中登录用户的session信息，又比如一些程序的监控日志，都是属于过了一定的时间就可以被覆盖的数据。
修改数据表名
>db.Account.renameCollection("Account1"){ "ok" : 1}
数据表帮助主题help
>db.Account.help()DBCollection help db.Account.find().help() - showDBCursor help db.Account.count() db.Account.dataSize() db.Account.distinct( key ) - eg.db.Account.distinct( 'x' ) db.Account.drop() drop the collection db.Account.dropIndex(name) db.Account.dropIndexes() db.Account.ensureIndex(keypattern[,options]) - options is an object withthese possible fields: name, unique, dropDups db.Account.reIndex() db.Account.find(,) -query is an optional query filter. fields is optional set of fields to return. e.g. db.Account.find( {x:77} , {name:1, x:1} ) db.Account.find(...).count() db.Account.find(...).limit(n) db.Account.find(...).skip(n) db.Account.find(...).sort(...) db.Account.findOne() db.Account.findAndModify( { update :... , remove : bool [, query: {}, sort: {}, 'new': false] } ) db.Account.getDB() get DB objectassociated with collection db.Account.getIndexes() db.Account.group( { key : ..., initial:..., reduce : ...[, cond: ...] } ) db.Account.mapReduce( mapFunction ,reduceFunction , <optional params> ) db.Account.remove(query) db.Account.renameCollection( newName ,<dropTarget> ) renames the collection. db.Account.runCommand( name ,<options> ) runs a db command with the given name where the first paramis the collection name db.Account.save(obj) db.Account.stats() db.Account.storageSize() - includesfree space allocated to this collection db.Account.totalIndexSize() - size inbytes of all the indexes db.Account.totalSize() - storageallocated for all data and indexes db.Account.update(query, object[,upsert_bool, multi_bool]) db.Account.validate() - SLOW db.Account.getShardVersion() - only foruse with sharding
查看全部表记录
>db.Account.find(){ "_id" :ObjectId("4df08553188e444d001a763a"), "AccountID" : 1,"UserName" : "libing", "Password" :"1", "Age" : 26, "Email" :"libing@126.com", "RegisterDate" : "2011-06-0916:31:25" }{ "_id" :ObjectId("4df08586188e444d001a763b"), "AccountID" : 2,"UserName" : "lb", "Password" : "1","Age" : 25, "Email" : "libing@163.com","RegisterDate" : "2011-06-09 16:36:95" }
--SELECT * FROMAccount
说明：
默认每页显示20条记录，当显示不下的情况下，可以用it迭代命令查询下一页数据。可以通过DBQuery.shellBatchSize设置每页显示数据的大小。如：DBQuery.shellBatchSize= 5，这样每页就显示5条记录了。
> db.Test.find(){ "_id" :ObjectId("4df6d55407444568af61cfea"), "TestID" : 1 }{ "_id" :ObjectId("4df6d55907444568af61cfeb"), "TestID" : 2 }{ "_id" :ObjectId("4df6d55b07444568af61cfec"), "TestID" : 3 }{ "_id" :ObjectId("4df6d55e07444568af61cfed"), "TestID" : 4 }{ "_id" :ObjectId("4df6d56207444568af61cfee"), "TestID" : 5 }{ "_id" :ObjectId("4df6d56507444568af61cfef"), "TestID" : 6 }{ "_id" :ObjectId("4df6d56807444568af61cff0"), "TestID" : 7 }{ "_id" :ObjectId("4df6d56b07444568af61cff1"), "TestID" : 8 }{ "_id" :ObjectId("4df6d56e07444568af61cff2"), "TestID" : 9 }{ "_id" :ObjectId("4df6d57a07444568af61cff3"), "TestID" : 10 }{ "_id" :ObjectId("4df6d57d07444568af61cff4"), "TestID" : 11 }{ "_id" :ObjectId("4df6d58007444568af61cff5"), "TestID" : 12 }{ "_id" :ObjectId("4df6d58307444568af61cff6"), "TestID" : 13 }{ "_id" :ObjectId("4df6d58e07444568af61cff7"), "TestID" : 14 }{ "_id" :ObjectId("4df6d59207444568af61cff8"), "TestID" : 15 }{ "_id" :ObjectId("4df6d59607444568af61cff9"), "TestID" : 16 }{ "_id" :ObjectId("4df6d59c07444568af61cffa"), "TestID" : 17 }{ "_id" :ObjectId("4df6d5a307444568af61cffb"), "TestID" : 18 }{ "_id" :ObjectId("4df6d5a607444568af61cffc"), "TestID" : 19 }>DBQuery.shellBatchSize20>DBQuery.shellBatchSize = 55> db.Test.find(){ "_id" :ObjectId("4df6d55407444568af61cfea"), "TestID" : 1 }{ "_id" :ObjectId("4df6d55907444568af61cfeb"), "TestID" : 2 }{ "_id" :ObjectId("4df6d55b07444568af61cfec"), "TestID" : 3 }{ "_id" :ObjectId("4df6d55e07444568af61cfed"), "TestID" : 4 }{ "_id" :ObjectId("4df6d56207444568af61cfee"), "TestID" : 5 }has more> it{ "_id" :ObjectId("4df6d56507444568af61cfef"), "TestID" : 6 }{ "_id" :ObjectId("4df6d56807444568af61cff0"), "TestID" : 7 }{ "_id" :ObjectId("4df6d56b07444568af61cff1"), "TestID" : 8 }{ "_id" :ObjectId("4df6d56e07444568af61cff2"), "TestID" : 9 }{ "_id" :ObjectId("4df6d57a07444568af61cff3"), "TestID" : 10 }has more> it{ "_id" :ObjectId("4df6d57d07444568af61cff4"), "TestID" : 11 }{ "_id" :ObjectId("4df6d58007444568af61cff5"), "TestID" : 12 }{ "_id" :ObjectId("4df6d58307444568af61cff6"), "TestID" : 13 }{ "_id" :ObjectId("4df6d58e07444568af61cff7"), "TestID" : 14 }{ "_id" :ObjectId("4df6d59207444568af61cff8"), "TestID" : 15 }has more> it{ "_id" :ObjectId("4df6d59607444568af61cff9"), "TestID" : 16 }{ "_id" :ObjectId("4df6d59c07444568af61cffa"), "TestID" : 17 }{ "_id" :ObjectId("4df6d5a307444568af61cffb"), "TestID" : 18 }{ "_id" :ObjectId("4df6d5a607444568af61cffc"), "TestID" : 19 }> itno cursor
查询一条记录
>db.Account.findOne(){ "_id" :ObjectId("4ded95c3b7780a774a099b7c"), "UserName" :"libing", "Password" : "1", "Email" :"libing@126.cn", "RegisterDate" :"2011-06-07 11:06:25"}--SELECT TOP 1 *FROM Account
查询聚集中字段的不同记录
>db.Account.distinct("UserName")--SELECTDISTINCT("UserName")FROMAccount
查询聚集中UserName包含“keyword”关键字的记录
db.Account.find({"UserName":/keyword/})--SELECT * FROM Account WHERE UserName LIKE '%keyword%'
查询聚集中UserName以"keyword"开头的记录
>db.Account.find({"UserName":/^keyword/})--SELECT * FROM Account WHEREUserName LIKE 'keyword%'
查询聚集中UserName以“keyword”结尾的记录
>db.Account.find({"UserName":/keyword$/})--SELECT * FROM Account WHEREUserName LIKE '%keyword'
查询聚集中指定列
>db.Account.find({},{"UserName":1,"Email":1}) --1:true--SELECTUserName,Email FROM Account
查询聚集中排除指定列
>db.Account.find({},{"UserName":0}) --0:false
查询聚集中指定列，且Age >20
>db.Account.find({"Age":{"$gt":20}},{"UserName":1,"Email":1})--SELECTUserName,Email FROM Account WHERE Age > 20
聚集中字段排序
>db.Account.find().sort({"UserName":1}) -- 升序>db.Account.find().sort({"UserName":-1}) --降序--SELECT * FROM AccountORDER BY UserName ASC
--SELECT * FROMAccount ORDER BY UserName DESC
统计聚集中记录条数
>db.Account.find().count()--SELECT COUNT(*) FROM Account
统计聚集中符合条件的记录条数
>db.Account.find({"Age":{"$gt":20}}).count()-- SELECTCOUNT(*) FROM Account WHERE Age > 20
统计聚集中字段符合条件的记录条数
>db.Account.find({"UserName":{"$exists":true}}).count()--SELECTCOUNT(UserName) FROM Account
查询聚集中前5条记录
>db.Account.find().limit(5)--SELECT TOP 5 * FROM Account
查询聚集中第10条以后的记录
>db.Account.find().skip(10)--SELECT * FROM Account WHERE AccountID NOT IN(SELECT TOP 10 AccountID FROM Account)
查询聚集中第10条记录以后的5条记录
>db.Account.find().skip(10).limit(5)--SELECT TOP 5 * FROM Account WHEREAccountID NOT IN (SELECT TOP 10 AccountID FROM Account)
or查询
>db.Account.find({"$or":[{"UserName":/keyword/},{"Email":/keyword/}]},{"UserName":true,"Email":true})--SELECTUserName,Email FROM Account WHERE UserName LIKE '%keyword%' OR Email LIKE'%keyword%'
添加新记录
>db.Account.insert({AccountID:2,UserName:"lb",Password:"1",Age:25,Email:"libing@163.com",RegisterDate:"2011-06-0916:36:95"})
修改记录
>db.Account.update({"AccountID":1},{"$set":{"Age":27,"Email":"libingql@163.com"}})>db.Account.find({"AccountID":1}){"AccountID" : 1, "Age" : 27, "Email" :"libingql@163.com", "Password" : "1","RegisterDate" : "2011-06-09 16:31:25","UserName" : "libing", "_id" :ObjectId("4df08553188e444d001a763a") }
>db.Account.update({"AccountID":1},{"$inc":{"Age":1}})>db.Account.find({"AccountID":1}){"AccountID" : 1, "Age" : 28, "Email" :"libingql@163.com", "Password" : "1","RegisterDate" : "2011-06-09 16:31:25","UserName" : "libing", "_id" :ObjectId("4df08553188e444d001a763a") }
删除记录
>db.Account.remove({"AccountID":1}) --DELETE FROM Account WHEREAccountID = 1
>db.Account.remove({"UserName":"libing"}) --DELETE FROMAccount WHERE UserName = 'libing'
>db.Account.remove({"Age":{$lt:20}}) --DELETE FROM Account WHERE Age< 20>db.Account.remove({"Age":{$lte:20}}) --DELETE FROM Account WHERE Age<= 20>db.Account.remove({"Age":{$gt:20}}) --DELETE FROM Account WHERE Age> 20>db.Account.remove({"Age":{$gte:20}}) --DELETE FROM Account WHERE Age>= 20>db.Account.remove({"Age":{$ne:20}}) --DELETE FROM Account WHERE Age!= 20
>db.Account.remove() --全部删除>db.Account.remove({})--全部删除
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